Fig. 4From: Bi5FeTi3O15 nanofibers/graphene nanocomposites as an effective counter electrode for dye-sensitized solar cells a Tafel-polarization curves of the symmetric cells fabricated with two identical CEs. b IPCE spectra of the DSSCs based on the BGr, Gr, and Pt CEs. c Current density-voltage curves (J-V). d, e CV curves for BGr, Gr, and Pt CEs. f Twenty cycles of CV curves from BGr2 CE at a scan rate of 50 mV/sBack to article page